Geographic Range

Tucuxis, also known as gray dolphins and Guianian River dolphins, are neotropical dolphins that live exclusively in the Amazon and Orinoco basins and are thought to be endemic to this region of South America. The closest living relatives of Tucuxis are Costeros, dolphins that live in the shallow waters along the Atlantic Coast of South America. However, Tucuxis are sympatric with Amazon River dolphins of the family Iniidae.